I. Field of the Invention
The present invention relates to grinding apparatus and more particularly to such apparatus suitable for providing axial and radial relief on cutting tools such as drilling and reaming bits, milling cutters and taps.
II. Description of the Prior Art
Cutting tools such as drilling and reaming bits are commonly provided with lands having leading cutting edges. Radial relief behind the cutting edges prevents drag against the wall of the hole being drilled or reamed. The relief necessarily extends some distance axially or along a portion of the length of the cutting tool.
Some cutting tools are provided with stepped diameters which during fabrication require both axial and radial relief along lengths of the cutting tool at several different diameters.
Such relief of cutting tools has heretofore been accomplished by mounting the cutting tool in a rotatable spindle which in turn is carried by a movable support operable to move the tool radially and/or axially into a grinding wheel. Means are provided to reciprocally move the support the required axial and radial distance to accomplish relief cutting for the particular cutting tool carried by the spindle.
In some prior art form relieving devices a cam having a number of uniformly dropping cam surfaces equal in number to the number of cutting edges on the cutting tool is secured to the spindle and cooperate with a cam follower. Such cams, however, are subject to manufacturing errors which cause corresponding errors in the cutting tool being ground or sharpened. Moreover, a different cam is required for each different cutting tool.